This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A172228 #24 Feb 16 2025 08:33:11
%S A172228 0,0,1,304,10741,127960,870589,4197456,16005187,51439096,145085447,
%T A172228 369074128,863338777,1883786680,3875953561,7583888944,14206566327,
%U A172228 25617069208,44663199283,75572017136,124485188701,200156902936,314851577749,485484612496,735056106571,1094434774968
%N A172228 Number of ways to place 5 nonattacking wazirs on an n X n board.
%C A172228 Wazir is a (fairy chess) leaper [0,1].
%H A172228 Vincenzo Librandi, <a href="/A172228/b172228.txt">Table of n, a(n) for n = 1..1000</a>
%H A172228 V. Kotesovec, <a href="https://oeis.org/wiki/User:Vaclav_Kotesovec">Number of ways of placing non-attacking queens and kings on boards of various sizes</a>
%H A172228 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/GridGraph.html">Grid Graph</a>
%H A172228 Wikipedia, <a href="http://en.wikipedia.org/wiki/Fairy_chess_piece">Fairy chess piece</a>
%H A172228 Wikipedia, <a href="https://en.wikipedia.org/wiki/Wazir_(chess)">Wazir (chess)</a>
%F A172228 a(n) = (n^10-50n^8+40n^7+995n^6-1560n^5-8890n^4+21080n^3+24264n^2-97440n+59520)/120, n>=4.
%F A172228 For any fixed value of k > 1, a(n) = n^(2k)/k! - 5/2/(k-2)!*n^(2k-2) + ...
%F A172228 G.f.: x^3 * (6*x^11 -26*x^10 -93*x^9 +527*x^8 +490*x^7 -6710*x^6 +13630*x^5 -3954*x^4 -26364*x^3 -7452*x^2 -293*x -1) / (x-1)^11. - _Vaclav Kotesovec_, Apr 29 2011
%F A172228 a(n) = A232833(n,5). - _R. J. Mathar_, Apr 11 2024
%t A172228 CoefficientList[Series[x^2 (6 x^11 - 26 x^10 - 93 x^9 + 527 x^8 + 490 x^7 - 6710 x^6 + 13630 x^5 - 3954 x^4 - 26364 x^3 - 7452 x^2 - 293 x - 1) / (x - 1)^11, {x, 0, 50}], x] (* _Vincenzo Librandi_, May 28 2013 *)
%Y A172228 Cf. A172225, A172226, A172227, A108792, A061998, A172129, A172136, A172140, A006506.
%K A172228 nonn,easy
%O A172228 1,4
%A A172228 _Vaclav Kotesovec_, Jan 29 2010
%E A172228 Corrected a(4) and g.f., _Vaclav Kotesovec_, Apr 29 2011.
%E A172228 More terms from _Vincenzo Librandi_, May 28 2013